Our History:
Nelson Precast first began manufacturing precast concrete products in 1952. As the famed marble steps of Baltimore City's rowhouses began to decay, precast stairs from Nelson were the preferred choice for both economy and durability. In fact, Nelson steps can be found on almost every street in Baltimore City.
Nelson Precast has drawn on this early experience and has since expanded to become one of the leading producers of custom cast stone and architectural precast in the region. Our products can be seen throughout the mid-Atlantic area, from New York to Virginia, and we have established ourselves as the first choice for many masons and general contractors in the region.
Our Mission:
Above all else, Nelson Precast seeks to establish and maintain lasting relationships with our clients. To do this, there are several things we must accomplish:
- Provide a complete, accurate, and easily checked scope with our estimates.
- Ensure that our submittal packages are complete and provided in a timely fashion.
- Work on our client's schedule, delivering pieces by phases as necessary, and not shipping stone before it is needed.
- Check every piece for color, quality, and dimensional accuracy.
- Provide extra pieces as needed, regardless of the reason, without undue hassle or delay.
Additionally, we wish to act as good members of both the local and global community. Our management and production staff are involved in a wide array of civic, charitable and artistic volunteer roles in the Baltimore region. In the summer of 2010, we were approached by ABC's hit series Extreme Makeover: Home Edition, who were building a new facility for Boys Hope/Girls Hope in Northeast Baltimore. We are proud that we were able to donate custom cast stone banding and sills to help make the new building a beautiful and inviting home. We also seek to minimize our environmental footprint, by taking such steps as using only locally quarried aggregates wherever possible. We have a LEED Accredited Professional as a member of our senior staff, and we continue to explore methods of further reducing our impact on the planet.
Our Process:
Design
Our design department is responsible for estimating, drafting, engineering, and custom color matching. All jobs, large and small, are assigned to a draftsman who guides their progress through the design process.
We view estimating as a part of the design department, rather than sales or administration. As a result, our estimators approach every takeoff from a design perspective. Our estimators are committed not to simply giving a lower price than our competitors, regardless of whether we can complete the job for that price, but to accurately determining the precise scope of the job and then giving the lowest possible price for that scope. As a result, we do not face the problem of unpleasant surprises leading to constant change orders and bruised relationships with clients. Our powerful and unique estimating software was written in-house as part of our overall project management system, and is specifically designed for speed, accuracy, and legibility. Our estimators are also skilled construction personnel, who are capable of answering customer questions and recognizing problematic conditions from the start, so that by the time we are awarded the job we have already begun the problem-solving process.
Once a job is awarded, our draftsmen immediately begin creating shop drawings using CAD. The commitment to accuracy which begins with our estimates continues with our drawings. Every individual precast piece will be shown, dimensioned, and clearly labeled. We design connections to the building structure, taking wind and seismic loads into account, and provide comprehensive engineering analyses as required by the specifications. Once drawings are accepted, detailed drawings of each piece are sent to the mold shop for production.
While our draftsmen are working, our mix design experts determine the mix to use for the job. While most of our jobs use one of our eight standard colors, we are frequently asked to match another color. Our mix designers blend different local aggregates and inorganic pigments to achieve a perfect color match, then process the stone to achieve the desired texture. We run repeated trials until we have several excellent matches, then submit them to the architect for approval.
Moldmaking
Our moldmakers combine technical proficiency in carpentry with artistic talent to assemble even the most complicated molds. Every piece must be cut precisely to size and assembled carefully so that every edge is perfectly square and true. Molds must also be sturdy enough to withstand the forces exerted during the production process, and must be completely sealed to prevent any moisture leakage.
Generally, our molds are made of wood, cut either by hand or with our CNC router. However, many of our moldmakers are skilled sculptors, capable of creating a perfect model from clay or plaster and using that to cast a rubber mold. For historical reproductions, our moldmakers will often spend many hours restoring an existing piece to its original condition so that it can be used as a model.
Moldmakers must have exceptional powers of spatial reasoning to convert two-dimensional drawings of a positive into a three-dimensional negative. The most complicated shapes, such as helices, require extensive geometrical calculations to reproduce as molds.
Production
Our 50,000 square foot production facility in West Baltimore is among the largest cast stone plants in the nation. Here, our skilled production crews manufacture, cure, and process all of our pieces, using both the vibrant dry-tamp and wet-pour methods as required for the job.
Our dry-tamp pieces are made by forcing a concrete mixture with an extremely low water-cement ratio into a mold using pneumatic pressure. After being produced, the pieces undergo accelerated curing in our custom-built curing chambers. This step, which many other cast stone manufacturers skip, dramatically increases long-term strength and durability. The pieces are then checked for dimensional accuracy, color, and overall quality before being processed, marked, palletized, and then left to continue curing in our indoor storage space. Once they have reached their shipping strength, they are shipped out to the job site.
Our wet-pour process utilizes our custom-built forming platforms. These platforms were built to extreme tolerances to ensure perfect flatness and smoothness. Our expert forming crews build our wet-pour forms directly on the platforms, guaranteeing perfectly square corners and dimensional tolerances. Our pouring crews then fill the forms with a concrete mixture designed for excellent flow characteristics and a high ultimate compressive strength. Once poured and cured under specialized heating blankets, the pieces are lifted clear of the platforms, checked, cleaned, and processed, and then stored indoors until they are ready to be shipped. Our large areas of secure indoor storage mean that we can easily ship finished pieces in precise batches as needed, rather than sending hundreds of disorganized pieces to an already crowded job site.
Both our dry-tamp and wet-pour production crews utilize our state of the art electronically controlled batch plant, which allows precise weight-based batching of aggregate, cement, water, pigment, and specialty admixtures. This allows us to produce highly consistent concrete with the specific properties required for the individual job.